Move SharePoint 2013 Search Index Location

#-----------------------------------------------------------------------------
# Name:               Move-SPEnterpriseSearchIndex.ps1 
# Description:      This script will move the SharePoint 2013 Search Index               
# Usage:               Run the function with the 3 required Parameters 
#-----------------------------------------------------------------------------

function Move-SPEnterpriseSearchIndex($SearchServiceName,$Server,$IndexLocation){
    Add-PSSnapin Microsoft.SharePoint.PowerShell -ea 0;
    #Gets the Search Service Application
    $SSA = Get-SPServiceApplication -Name $SearchServiceName;
    if (!$?){throw "Cant find a Search Service Application: `"$SearchServiceName`"";}
    #Gets the Search Service Instance on the Specified Server
    $Instance = Get-SPEnterpriseSearchServiceInstance -Identity $Server;
    if (!$?){throw "Cant find a Search Service Instance on Server: `"$Server`"";}
    #Gets the current Search Topology
    $Current = Get-SPEnterpriseSearchTopology -SearchApplication $SSA -Active;
    if (!$?){throw "There is no Active Topology, you can try removing the `"-Active`" from the line above in the script";}
    #Creates a Copy of the current Search Topology
    $Clone = New-SPEnterpriseSearchTopology -Clone -SearchApplication $SSA -SearchTopology $Current;
    #Adds a new Index Component with the new Index Location
    New-SPEnterpriseSearchIndexComponent -SearchTopology $Clone -IndexPartition 0 -SearchServiceInstance $Instance -RootDirectory $IndexLocation | Out-Null;
    if (!$?){throw "Make sure that Index Location `"$IndexLocation`" exists on Server: `"$Server`"";}
    #Sets our new Search Topology as Active
    Set-SPEnterpriseSearchTopology -Identity $Clone;
    #Removes the old Search Topology
    Remove-SPEnterpriseSearchTopology -Identity $Current -Confirm:$false;
    #Now we need to remove the extra Index Component
    #Gets the Search Topology
    $Current = Get-SPEnterpriseSearchTopology -SearchApplication $SSA -Active;
    #Creates a copy of the current Search Topology
    $Clone=New-SPEnterpriseSearchTopology -Clone -SearchApplication $SSA -SearchTopology $Current;
    #Removes the old Index Component from the Search Topology
    Get-SPEnterpriseSearchComponent -SearchTopology $Clone | ? {($_.GetType().Name -eq "IndexComponent") -and ($_.ServerName -eq $($Instance.Server.Address)) -and ($_.RootDirectory -ne $IndexLocation)} | Remove-SPEnterpriseSearchComponent -SearchTopology $Clone -Confirm:$false;
    #Sets our new Search Topology as Active
    Set-SPEnterpriseSearchTopology -Identity $Clone;
    #Removes the old Search Topology
    Remove-SPEnterpriseSearchTopology -Identity $Current -Confirm:$False;
    Write-Host "The Index has been moved to $IndexLocation on $Server"
    Write-Host "This will not remove the data from the old index location. You will have to do that manually :)"
}


Move-SPEnterpriseSearchIndex -SearchServiceName "Search Service Application" -Server "SP2013-WFE" -IndexLocation "C:\Index"

 SharePoint 2013 places the Search index in the C: by default. There are many reasons why you would want to move the index to a different places.
This script will take three parameters, the Search Service Name, the Server Name and Index Location.  There is an example on the bottom of the script.